Skip directly to site content Skip directly to search


Español  Other Languages


Centers for Disease Control and Prevention. CDC twenty four seven. Saving Lives, Protecting People
 Search

		Submit


Tuberculosis (TB)








Reported Tuberculosis in the United States, 2022						Print
																Related Pages
										Return to Main Menu
Appendix B****
(Revised August 11, 2023)
Recommendations for Counting Reported Tuberculosis Cases were first published in July 1997. Since that time, substantial changes have occurred, and questions have been raised within the field of tuberculosis (TB) surveillance. This document is reviewed annually, and minor modifications and clarifications are incorporated.
A distinction should be made between reporting TB cases to a health department and countingTB cases for determining disease incidence. Throughout each year, TB cases and persons being evaluated for TB are reported to public health authorities by such sources as clinics, hospitals, laboratories, and health care providers. From these reports, the state or local TB control officer must determine which cases meet the surveillance definition for TB disease and whether the case is countable. These countable TB cases are then reported to the Centers for Disease Control and Prevention (CDC).
Beginning in 2009, state and local TB control officers also report to CDC those TB cases that are verified but not countable for morbidity statistics, as a measure of programmatic and case management burden. Noncountable cases include persons with TB disease recurring within a consecutive 12-month period after the patient completed TB therapy.
I. Reporting TB Cases
CDC recommends that health care providers and laboratories be required to report all TB cases or persons being evaluated for TB to state and local health departments based on “Tuberculosis Case Definition for Public Health Surveillance” (Appendix A). This notification is essential for TB programs to
ensure case supervision,
ensure completion of recommended therapy,ensure completion of contact investigations,
evaluate program effectiveness, and
assess trends and characteristics of TB morbidity.II. TB Surveillance
For purposes of surveillance, a case of TB is defined based on laboratory or clinical evidence of active disease caused by M. tuberculosis complex*
*Because many laboratories use tests that do not routinely distinguish Mycobacterium tuberculosis from closely related species, these laboratories report culture results as being positive or negative for “Mycobacterium tuberculosis complex.” Species in the *M. tuberculosis* complex include *Mycobacterium bovis*, *Mycobacterium africanum*, *Mycobacterium orygis*, *Mycobacterium microti*, *Mycobacterium canettii*, *Mycobacterium caprae*, *Mycobacterium pinnipedii*, *Mycobacterium suricattae*, and *Mycobacterium mungi*. Although in almost all cases of human disease, isolates in the *M. tuberculosis* complex are, in fact, *M. tuberculosi*s, other species are possible. In terms of their ability to cause clinical disease or be transmissible from person to person, *M. bovis*, *M. africanum*, *M. orygis*, *M. microti*, *M. canettii*, *M. caprae*, *M. pinnipedii*, and *M. mungi* behave like *M. tuberculosis*; therefore, disease caused by any of the organisms should be reported as TB, using the Report of Verified Case of TB (RVCT). The only exception is the bacillus Calmette-Guérin (BCG) strain of *M. bovis*, which can be isolated from persons who have received the vaccine for protection against TB or as cancer immunotherapy; disease caused by the BCG strain of *M. bovis* should **not** be reported as TB.
Laboratory Case Definitionisolation ofM. tuberculosiscomplex from a clinical specimen. Use of rapid identification techniques forM. tuberculosisperformed on a culture from a clinical specimen (e.g., DNA probes or high-pressure liquid chromatography) is acceptable under this criterion.
or
demonstration ofM. tuberculosisfrom a clinical specimen by nucleic acid amplification test. Nucleic acid amplification tests (NAAT) must be accompanied by cultures of mycobacterial species. However, for surveillance purposes, CDC will accept results obtained from NAAT approved by the Food and Drug Administration (FDA) and used according to the approved product labeling on the package insert, or a test produced and validated in accordance with applicable FDA and Clinical Laboratory Improvement Amendments regulations.
or
demonstration of acid-fast bacilli (AFB) in a clinical specimen when a culture has not been or cannot be obtained or is falsely negative or contaminated. Historically, this criterion has been most commonly used in diagnosing TB in the postmortem setting.
Clinical Case DefinitionIn the absence of laboratory confirmation ofM. tuberculosiscomplex after a diagnostic process has been completed, persons must haveallof the following criteria for a clinical TB diagnosis:
evidence of TB infection based on a positive tuberculin skin test result or positive interferon-gamma release assay fortuberculosis, and current treatment with ≥2 anti-TB medications;and
1 of the following:
signs and symptoms compatible with current TB disease (e.g., an abnormal chest radiograph or abnormal chest computerized tomography scan or other chest imaging study);or
clinical evidence of current disease (e.g., fever, night sweats, cough, weight loss, hemoptysis).NOTE:The software for TB surveillance developed by CDC includes a calculated variable called “VERCRIT,” for which one of the values is Provider Diagnosis. Provider Diagnosis is selected when the user chooses to override a Suspect (i.e., presumptive TB case or person being evaluated for TB disease) default value in the case verification screen as Verified by Provider Diagnosis. Thus, Provider Diagnosis is not a component of the case definition for TB in the “TB Case Definition for Public Health Surveillance” (Appendix A). CDC’s national morbidity reports have traditionally included all TB cases that are considered verified by the reporting areas, without a requirement that cases meet the published case definition.
III. Counting TB Cases
Cases that meet the CDC surveillance case definition for verified TB are counted by 52 reporting areas with count authority (50 U.S. states, the District of Columbia, and New York City) to determine annual incidence for the United States. The remaining eight reporting areas (American Samoa, Federated States of Micronesia, Guam, Republic of the Marshall Islands, Commonwealth of the Northern Mariana Islands, Puerto Rico, Republic of Palau, and the U.S. Virgin Islands) report cases to CDC but are not included in the annual incidence for the United States. The laboratory and clinical case definitions are the two diagnostic categories used in the CDC “Tuberculosis Case Definition for Public Health Surveillance” (Appendix A).
The majority of verified TB cases are accepted for counting on the basis of laboratory confirmation ofM. tuberculosiscomplex from a clinical specimen.
A person might have >1 discrete (separate and distinct) episode of TB. If disease recurswithinany twelve-month consecutive period after the patient completed therapy, count only 1 episode as a case. However, if TB disease recurs in a person,andif >12 months have elapsed since the person completed TB therapy or since the person was lost to supervision, the TB case is considered a separate episode and should be counted as a new case.
Mycobacterial diseases other than those caused byM. tuberculosiscomplex should not be counted in TB morbidity statistics unless concurrent TB occurs.
A. Verified TB Cases
CASES THAT SHOULD BE COUNTED
Only verified TB cases that meet the laboratory or clinical case definitions should be counted (see Section II). TB diagnosis must be verified by the TB control officer or designee. The CDC surveillance case definition for TB (Appendix A) describes and defines the criteria to be used in the case definition for TB disease.
CASES THAT SHOULDNOTBE COUNTED
If diagnostic procedures have not been completed, TB should be confirmed before the case is counted. A case of illness should not be counted in a patient for whom ≥2 anti-TB medications have been prescribed for preventive therapy for exposure to multidrug-resistant TB or while the diagnosis is still pending.
B. Nontuberculous Mycobacterial Disease
CASES THAT SHOULD BE COUNTED
An episode of TB disease diagnosed concurrently with another nontuberculous mycobacterial disease (NTM) should be counted as a TB case.
CASES THAT SHOULDNOTBE COUNTED
Disease attributed to or caused by NTM alone should not be counted as a TB case.
C. TB Cases Reported at Death
CASES THAT SHOULD BE COUNTED
TB cases first reported to the health department at the time of a person’s death are counted as incident cases, provided the person had current disease at the time of death. The TB control officer should verify the TB diagnosis.
CASES THAT SHOULDNOTBE COUNTED
A case of TB should not be counted if no evidence exists of current disease at the time of death or at autopsy.
D. Immigrants, Refugees, Permanent Resident Aliens, Foreign Visitors, and Border Crossers†
CASES THAT SHOULD BE COUNTED
Persons who are examined after arriving in the United States and are diagnosed with clinically active TB disease requiring TB treatment should be counted by the locality where the diagnostic evaluation for TB began, regardless of citizenship or residency status.
In addition, border crossers†who receive TB treatment from a U.S. locality for a total of ≥90 consecutive days (excluding weekends) should be counted by the locality where they receive treatment.
Foreign visitors (e.g., students, commercial representatives, and diplomatic personnel) who receive a diagnosis of TB, are receiving TB treatment, and have been in the United States for ≥90 days should be counted by the locality of current residence.
CASES THAT SHOULDNOTBE COUNTED
Any person who received a TB diagnosis and who started TB treatment in another country should not be counted as a new case but should be reported as a person with a verified noncountable TB case.
Border crossers† and other foreign visitors who are in the United States for <90 days total and begin TB treatment in the United States but return to their native country to continue therapy should not be reported or counted by the U.S. locality where they receive treatment.
†Border crosseris defined by U.S. Citizenship and Immigration Services1as “an alien resident of the United States reentering the country after an absence of less than six months in Canada or Mexico, or a nonresident alien entering the United States across the Canadian border for stays of no more than six months, or across the Mexican border for stays of no more than 72 hours.” Border crossers might go back and forth across the border frequently during a short period.
E. Out-of-State or Out-of-Area Residents
CASES THAT SHOULD BE COUNTED
A person’s TB case should be counted by the locality in which he or she resides at the time of diagnosis. TB in a person who has no address should be counted by the locality where TB is diagnosed and treated. The TB control officer should notify the out-of-state or out-of-area TB control officer of the person’s home locality to (1) determine whether the case has been counted already to avoid double counting, and (2) agree on which TB control office should count the case if it has not yet been counted.
CASES THAT SHOULD *NOT* BE COUNTED
A case in a patient with newly diagnosed TB who is an out-of-area resident and whose TB has already been counted by the out-of-area TB control office should not be counted.
F. Migrants and Other Persons with Transient Living Arrangements
CASES THAT SHOULD BE COUNTED
Persons without any fixed U.S. residence are considered to be the public health responsibility of their present locality, and their TB case should be counted by the locality where the diagnostic evaluation that led to the TB diagnosis was initiated.
CASES THAT SHOULDNOTBE COUNTED
Cases among transient TB patients should not be counted when evidence exists that they have already been counted by another locality (e.g., because they began treatment before arriving in the present locality).
G. Cases Occurring in Federal Facilities (e.g., Military and Veterans Administration Facilities)
CASES THAT SHOULD BE COUNTED
Cases among military personnel, their dependents, or veterans should be reported and counted by the locality where the persons are residing in the United States at the time of diagnosis and initiation of treatment. However, if military personnel or dependents are discovered to have TB at a military base outside the United States but are referred elsewhere for treatment (e.g., a military base located within the United States), the TB case should be reported and counted where treatment is administered and not where the diagnosis was made.
CASES THAT SHOULDNOTBE COUNTED
A case that was already counted by another locality in the United States should not be counted.
H. Cases Associated with the Indian Health Service
CASES THAT SHOULD BE COUNTED
TB should be reported to the local health authority (e.g., state or county) and counted where diagnosed and treatment is initiated. However, for specific groups (e.g., the Navajo Nation) located across multiple states, health departments should discuss each case and determine which locality should count the case.
CASES THAT SHOULDNOTBE COUNTED
A case should not be counted if the case was already counted by another locality.
I. Cases Occurring in Correctional Facilities (e.g., Local, State, Federal, and Military)
CASES THAT SHOULD BE COUNTED
Frequently, persons who reside in local, state, federal, or military correctional facilities are transferred or relocated within or between different correctional facilities. TB among these persons should be reported to the local health authority and counted by the locality where the diagnostic evaluation that led to the TB diagnosis was initiated.
CASES THAT SHOULDNOTBE COUNTED
Correctional facility residents’ TB cases that were counted elsewhere by another locality or correctional facility, even if treatment continues at another locale or correctional facility, should not be counted.
J. Peace Corps, Missionaries, and Other Citizens Residing Outside the United States
CASES THAT SHOULDNOTBE COUNTED
TB among persons who received their diagnosis outside the United States should not be counted. TB among these persons should be counted by the country in which they are residing, regardless of their plans to return to the United States for further evaluation or treatment.
IV. Recommended Administrative Practices
To promote uniformity in TB case counting, the following administrative procedures are recommended:
All TB cases verified by the 52 reporting areas with count authority (50 U.S. states, DC, and New York City) during the calendar year (by December 31) will be included in the annual U.S. incidence count for that year. All TB cases verified during the calendar year by a reporting area with count authority from 1 of the remaining 8 reporting areas (American Samoa, Federated States of Micronesia, Guam, Republic of the Marshall Islands, Commonwealth of the Northern Mariana Islands, Puerto Rico, Republic of Palau, and the U.S. Virgin Islands) are also counted but are not included in the annual incidence for the United States. Cases for which bacteriologic results are pending or for which confirmation of disease is questionable for any other reason should not be counted until their status is clearly determined; they should be counted at the time they meet the criteria for counting. This means that a case reported in 1 calendar year might be included in the morbidity count for the following year. All reporting areas should ensure that agreement exists between final local and state TB figures reported to CDC. Reporting areas might not use this recommended protocol. They may wait until the beginning of the following year when they have received and processed all of the TB cases for inclusion in the annual case count for the previous year. If reporting areas decide to revise their protocols, they should be aware that their TB trends might change.
Occasionally, TB is reported to health departments by telephone, by letter or fax, or on forms other than the RVCT. Such information should be accepted as an official morbidity report if sufficient details are provided; otherwise, the notification should be used as an indicator of a possible TB case that should be investigated promptly for confirmation.V. Glossary of TB Surveillance Terms
case:an episode of TB disease in a person meeting the laboratory or clinical criteria for TB, as defined in “Tuberculosis Case Definition for Public Health Surveillance” (see Section II for criteria).
counting of a TB case:the process whereby a reporting area with count authority evaluates verified TB cases against count criteria (e.g., assesses for case duplication). These cases are then counted for morbidity in that locality (e.g., state or county) and reported to CDC for national morbidity counting. Noncountable, verified cases should also be sent to CDC.
Mycobacterium tuberculosiscomplex:a genetically related group of *Mycobacterium* species that can cause TB in humans or other animals. Because the majority of laboratories use tests that do not routinely distinguish *M. tuberculosis* from closely related species, those laboratories report culture results as being positive or negative for *M. tuberculosis* complex. Species in the *M. tuberculosis* complex include *Mycobacterium bovis*, *Mycobacterium africanum*, *Mycobaterium orygis*, *Mycobacterium microti*, *Mycobacterium canettii*, *Mycobacterium caprae*, *Mycobacterium pinnipedii*, *Mycobacterium suricattae*, and *Mycobacterium mungi*. Although in most cases of human disease, isolates in the *M. tuberculosis* complex are, in fact, *M. tuberculosis*, other species are possible. In the United States, 1.5%–1.9% of genotyped cases are cause by *Mycobacterium bovis*; cultures from these cases would be reported by the majority of laboratories as being positive for *M. tuberculosis* complex.2 In terms of their ability to cause clinical disease or be transmissible from person to person, *M. bovis, M. africanum, M. orygis, M. microti, M. canettii, M. caprae,* and *M. pinnipedii* behave similar to *M. tuberculosis*; therefore, disease caused by any of the organisms should be reported as TB by using the RVCT form. The only exception is the bacillus Calmette-Guérin (BCG) strain of *M. bovis*, which might be isolated from persons who have received the vaccine for protection against TB or as cancer immunotherapy; disease caused by the BCG strain of *M. bovis* should not be reported as TB.
**nontuberculous mycobacteria:** mycobacteria other than *M. tuberculosis* complex that can cause human infection or disease. Common nontuberculous mycobacteria (NTM) include *Mycobacterium avium* complex (also known as “MAC” (*Mycobacterium avium*  or *Mycobacterium intracellulare*), *Mycobacterium kansasii*, *Mycobacterium marinum*, *Mycobacterium scrofulaceum*, *Mycobacterium chelonae*, *Mycobacterium fortuitum*, and *Mycobacterium simiae*. Other terms have been used to represent NTM, including “MOTT” (mycobacteria other than TB) and “atypical” mycobacteria.
reporting area:areas responsible for counting and reporting verified TB cases to CDC. A total of 60 areas report cases to CDC: the 50 U.S. states, the District of Columbia (D.C.), New York City, American Samoa, Federated States of Micronesia, Guam, Republic of the Marshall Islands, Commonwealth of the Northern Mariana Islands, Puerto Rico, Republic of Palau, and the U.S. Virgin Islands. The annual incidence of TB for the United States is based on 52 of these reporting areas (the 50 U.S. states, D.C., and New York City).
suspected TB case:a case for which a high index of suspicion exists for active TB disease (e.g., a person with signs or symptoms consistent with TB) and that is currently under evaluation.  However, “possible TB case,” “presumptive TB case” or “person being evaluated for TB” is preferred.
verification of a TB case:the process whereby a TB case, after the diagnostic evaluation is complete, is reviewed at the local level (e.g., state or county) by a TB control official who is familiar with TB surveillance definitions; if all the criteria for a TB case are met, the TB case is then verified and eligible for counting.ReferencesUS Department of Homeland Security (DHS). U.S. Citizenship and Immigration Services [Homepage]. Washington, DC: DHS; 2016.
Centers for Disease Control and Prevention. Reported Tuberculosis in the United States, 2021. Accessed August 26, 2022. https://www.cdc.gov/tb/statistics/reports/2021/default.htm
							
					
							Last Reviewed:  November 15, 2023						Source: 	Division of Tuberculosis Elimination, National Center for HIV, Viral Hepatitis, STD, and TB Prevention, Centers for Disease Control and Prevention
					Facebook
        Twitter
        LinkedIn
        Syndicate homeTuberculosisBasic TB Factsplus iconHow TB SpreadsLatent TB Infection and TB DiseaseSigns & SymptomsTB Risk FactorsExposure to TBTB PreventionVaccinesTB & HIV CoinfectionTB and DiabetesTB TermsPersonal StoriesTesting & Diagnosisplus iconWho Should be TestedTesting for TB InfectionTesting in BCG-Vaccinated PersonsTB Screening and Testing of Health Care PersonnelTesting During PregnancyDiagnosing latent TB infection and TB diseaseTreatmentplus iconDeciding When to Treat Latent TB InfectionTreatment Regimens for Latent TB Infection (LTBI)Treatment for TB DiseaseAdverse EventsTB Treatment of Persons Living with HIVTB Treatment and PregnancyTB Treatment for ChildrenFrequently Asked QuestionsDrug-Resistant TBResearchplus iconTB Epidemiologic Studies Consortiumplus iconResearch ProjectsPublicationsTB Trials Consortiumplus iconStudy DescriptionsBackgroundBehavioral & Social Science ResearchHealth Care Settingsplus iconTB Infection Control in Health Care SettingsResources for TB Screening and Testing of Health Care Personnelplus iconFrequently Asked QuestionsTB in Specific Populationsplus iconHealth DisparitiesAsian PersonsBlack or African American PersonsHispanic or Latino PersonsChildrenPregnancyCorrectional FacilitiesPeople Experiencing HomelessnessInternational TravelersLaboratory Informationplus iconDrug Susceptibility TestingFalse-Positive Investigation ToolkitInterim Laboratory Biosafety Guidance for XDR  tuberculosis strainsModel Performance Evaluation Program (MPEP)Rapid Molecular Testing to Detect Drug-Resistant TB in the USplus iconExecutive SummaryIntroductionBackground on Tests for Molecular Detection of DRGeneral Considerations and Principles for a Molecular DR Testing ServicePossible Scenarios and Scope of Testing for a Molecular DR Testing ServiceResearch NeedsGeneral Recommendations of the Expert PanelCommunication Plan for the ReportRecommendationsReferencesPanel Members and CDC ParticipantsAppendix 1Appendix 2Appendix 3The Uses of Nucleic Acid Amplification Tests for the Diagnosis of TBplus iconGeneral ConsiderationsGeneral Recommendations of the Expert PanelRecommendations to ACET, CDC, DTBEData & Statisticsplus iconTB Incidence in the United StatesReported TB in the US, 2022 Surveillance Reportplus iconNational DataReporting Area DataRisk FactorsDemographicsTB Treatment and Case OutcomesDrug-Resistant TBMolecular SurveillanceTuberculosis in the United States, 2022 (Slide Set)Archived Surveillance Reports and Slide Sets2021 State and City ReportArchived State and City ReportsProfessional Resources & Toolsplus iconTools for Healthcare ProvidersResources for TB Programsplus iconStrengthening Civil Surgeons’ Capacity to Improve LTBI Surveillance and Outcomes Among Status AdjustersNotice of Funding Opportunity (NOFO)Program EvaluationTB Centers of ExcellenceTB Elimination AllianceTB Genotypingplus iconConventional TB GenotypingWhole Genome SequencingTB GIMSAnalytic ToolsLatent Tuberculosis Infection ResourcesPublications & Productsplus iconPatient and Public MaterialsFact SheetsGuidelinesplus iconControl & EliminationDrug-Resistant TBInfection Control & PreventionLaboratory & GenotypingTB & HIVTB in Specific PopulationsTesting & DiagnosisTreatmentVaccines & ImmunizationsArchived TB GuidelinesGuides & Toolkitsplus iconAggregate ReportsCDC TB Surveillance TrainingCore CurriculumEffective TB Interviewing for Contact InvestigationEthnographic GuidesFalse-Positive Investigation ToolkitForging Partnerships to Eliminate TuberculosisGuide to Application of GenotypingLTBI: A Guide for Primary Health Care ProvidersMantoux Tuberculin Skin Testing ProductsReport of Verified Case of Tuberculosis (RVCT)Self-Study ModulesTB Contact Investigation Interviewing Skills CourseTB eDOT ToolkitUnderstanding the TB Cohort Review ProcessNewslettersplus iconTB Notes, No. 4, 2023TB Notes, No. 3, 2023TB Notes. No. 2, 2023TB Notes. No. 1, 2023TB Notes, No. 4, 2022TB Notes, No. 3, 2022TB Notes, No. 2, 2022TB Notes, No. 1, 2022TB Notes, No. 4, 2021TB Notes, No. 3, 2021TB Notes, No. 2, 2021TB Notes, No. 1, 2021Pamphlets, Brochures, Bookletsplus iconQuestions and AnswersPatient Education SeriesTuberculosis - Get the FactsTuberculosis - The Connection between TB and HIV12-Dose Regimen for Latent TB Infection-Patient Education BrochurePostersplus iconMantoux Tuberculin Skin Test Wall ChartWorld TB DayThink TBStop TBTake on TBReports & Articlesplus iconDTBE Authored Journal ArticlesTuberculosis Laboratory Aggregate ReportsSlide Setsplus iconIntroduction to TuberculosisEpidemiology of Tuberculosis Among Non-U.S.​–Born Persons in the United States, 1993–2016Self-Study Modules on Tuberculosis, 1-5 Slide SetsThe Tuberculosis (TB) in Correctional Settingsplus iconFacilitator GuideIntroduction to TB GenotypingEpidemiology of Tuberculosis in Correctional Facilities, United States, 1993-2017Prevention and Control of Tuberculosis in Correctional and Detention FacilitiesGuidelines for Preventing the Transmission of M. TB in Health care SettingsInvestigation of Contacts of Persons with Infectious TBEpidemiology of Pediatric Tuberculosis in the United StatesTargeted Tuberculosis Testing and Treatment of Latent Tuberculosis InfectionElectronic Tools & ResourcesWeb-Based Courses & Webinarsplus iconTB 101 for Health Care WorkersContent SyndicationInfographicsplus iconSocial Media GraphicsCustomizable Take on TB Infographic with InstructionsEventsWorld TB Dayplus iconU.S. TB ChampionsHistoryFeaturesplus iconTB Risk FactorsTreating Latent TB Infection with Short-Course RegimensWorld Tuberculosis (TB) Day 2021World Tuberculosis (TB) Day 2020Linksplus iconState TB Control OfficesAbout Usplus iconMission Statement and Activitiesplus iconDTBE Strategic PlanNational TB Program ObjectivesOrganization ChartAdvisory Groupsplus iconFederal TB Task Force To receive email updates about this page, enter your email address: Email Address			What's this?				Submit


About CDC
					Contact Us
					800-232-4636
 Facebook Twitter Instagram LinkedIn Youtube Pinterest Snapchat
 CONTACT CDC
				Contact Us
							Call 800-232-4636
							Email Us
			ABOUT CDC
				About CDC
							Jobs
							Funding
			POLICIES
				Accessibility
							External Links
							Privacy
							Policies
							No Fear Act
							FOIA
							OIG
							Nondiscrimination
							Vulnerability Disclosure Policy
			CONNECT WITH US
				Facebook
								Twitter
								Instagram
								LinkedIn
							Youtube
								Pinterest
								Snapchat
								Email
			LANGUAGES
				Español
							繁體中文
							Tiếng Việt
							한국어
							Tagalog
							Русский
							العربية
							Kreyòl Ayisyen
							Français
							Polski
							Português
							Italiano
							Deutsch
							日本語
							فارسی
							English


U.S. Department of Health & Human Services
			Accessibility
			External Links
			Privacy
			Policies
			No Fear Act
			FOIA
			Nondiscrimination
			OIG
			Vulnerability Disclosure Policy
			USA.gov


Exit Notification / Disclaimer Policy Close
 Links with this icon  indicate that you are leaving the CDC website. The Centers for Disease Control and Prevention (CDC) cannot attest to the accuracy of a non-federal website.
				Linking to a non-federal website does not constitute an endorsement by CDC or any of its employees of the sponsors or the information and products presented on the website.
				You will be subject to the destination website's privacy policy when you follow the link.
				CDC is not responsible for Section 508 compliance (accessibility) on other federal or private website. Website Disclaimers
 Cancel Continue